FAMILY CORYNEBACTERIACEAE 



399 



Aerobic . 



Source: From witches' brooms. 

 Habitat : Pathogenic on Eugenia lati- 

 folia. 



2. Corynebacterium flaccumfaciens 

 (Hedges) Dowson. {Bacterium flaccum- 

 faciens Hedges, Science, 55, 1922, 433; 

 Phytopath., 16, 1926, 20; Phytomonas 

 flaccumfaciens Bergey et al.. Manual, 

 1st ed., 1923, 178; Pseudomonas flac- 

 cumfaciens Stevens, Plant Diseases of 

 Fungi, 1925, 27; Dowson, Brit. Myc. 

 Soc. Trans., 25, 1942, 313.) From Latin 

 flaccus, flabby or wilted; facio, to make; 

 producing a wilt. 



Rods: 0.3 to 0.5 by 0.6 to 3 microns. 

 Motile with a single polar flagellum; 

 also non-motile (Adams and Pugsley, 

 Jour. Dept. Agr. Victoria., 32, 1934, 306). 

 Gram-positive. 



Gelatin: Liquefaction feeble. 



Beef agar slants : Rather moderate 

 growth, glistening, flat, smooth, viscid 

 and yellow. 



Broth : Moderate turbidity in 24 hours. 

 Pellicle formed. 



Milk: Acid curd and slow peptoniza- 

 tion. 



Nitrites not produced from nitrates. 



Indole not formed. 



Xo H,S formed. 



Acid from glucose, lactose, sucrose and 

 glycerol. 



Starch not hydrolyzed. 



Slight growth in 5 per cent salt. 



Optimum temperature, 31°C. Maxi- 

 mum temperature 36° to 40°C. 



Distinctive character : A strict vascular 

 parasite of the bean. 



Source : From wilted bean plants from 

 South Dakota. 



Habitat : Causes a wilt of beans and 

 related plants. 



3. Corynebacteritun poinsettiae Starr 

 and Pirone. (Phytopath., 32, 1942, 1080 ; 

 Phytomonas 'poinsettiae, ibid.) From 

 M. L., old genus Poinsettia. 



Rods: Average cells 0.3 to 0.8 by 1.0 

 to 3.0 microns. Pleomorphic with some 

 cells 8.5^microns in length. Granules 



and capsules present. Motile with 1 

 (rarely 2) polar or lateral flagellum. 

 Gram-positive. 



Gelatin: Liquefaction. 



Loeffler's bloo d -serum : Liquefaction. 



Beef-e.xtract agar colonies : Roimd, 

 slightly convex, 0.1 to 1.0 mm in di- 

 ameter, edges entire, smooth, non-viscid, 

 colorless and almost transparent. 



Potato glucose agar slants : Moderate 

 growth, filiform, glistening, non-viscid, 

 salmon to flesh color. 



Beef -extract broth : Turbid in 24 hours, 

 abundant pale salmon sediment. No 

 pellicle. 



Milk : Slight acidity but no other 

 visible change for 2 weeks, then a soft 

 curd, reduction of litmus, and complete 

 peptonization. 



Indole not produced. 



Nitrites not produced from nitrates. 



Hj'drogen sulfide not formed. 



Sodium hippurate not hydrolyzed. 



Asparagine not utilized as carbon- 

 nitrogen source. Uric acid not utilized; 

 urea not hydrolyzed. 



No lipolytic activity. 



Voges-Proskauer test negative. 

 Methyl red test negative. 



^loderate to abundant acid, but no 

 gas, from glucose, fructose, mannose, 

 galactose, sucrose, maltose, cellobiose, 

 melibiose, raffinose, glycerol, erythritol, 

 salicin and amygdalin ; weak acid from 

 arabinose, xylose, lactose, trehalose, dex- 

 trin and adonitol ; no acid from rhamnose, 

 fucose, inulin, glycogen, mannitol, dulci- 

 tol, sorbitol and inositol. 



Starch hydrolyzed. 



No action on cellulose. 



Tellurite reduced. 



Aerobic. 



Growth occurs after 24 hours from 15°C 

 to 36°C ; after 48 hours from 7°C to 12°C. 

 No growth above 36°C or below 7°C at 

 the end of a week. 



Source : Fourteen cultures isolated 

 from diseased stems of poinsettia, 

 Euphorbia pulcherrima. 



Habitat : Causes a canker of stem s and 

 spots on leaves of the poinsettia. 



